1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License, Version 1.0 only
6 * (the "License").  You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22/*
23 * Copyright (c) 2001 by Sun Microsystems, Inc.
24 * All rights reserved.
25 */
26
27#pragma ident	"@(#)stack.c	1.3	05/06/08 SMI"
28
29/*
30 * Routines for manipulating stacks
31 */
32
33#include <stdio.h>
34#include <assert.h>
35#include <stdlib.h>
36
37#include "stack.h"
38#include "memory.h"
39
40#define	STACK_SEEDSIZE	5
41
42struct stk {
43	int st_nument;
44	int st_top;
45	void **st_data;
46
47	void (*st_free)(void *);
48};
49
50stk_t *
51stack_new(void (*freep)(void *))
52{
53	stk_t *sp;
54
55	sp = xmalloc(sizeof (stk_t));
56	sp->st_nument = STACK_SEEDSIZE;
57	sp->st_top = -1;
58	sp->st_data = xmalloc(sizeof (void *) * sp->st_nument);
59	sp->st_free = freep;
60
61	return (sp);
62}
63
64void
65stack_free(stk_t *sp)
66{
67	int i;
68
69	if (sp->st_free) {
70		for (i = 0; i <= sp->st_top; i++)
71			sp->st_free(sp->st_data[i]);
72	}
73	free(sp->st_data);
74	free(sp);
75}
76
77void *
78stack_pop(stk_t *sp)
79{
80	assert(sp->st_top >= 0);
81
82	return (sp->st_data[sp->st_top--]);
83}
84
85void *
86stack_peek(stk_t *sp)
87{
88	if (sp->st_top == -1)
89		return (NULL);
90
91	return (sp->st_data[sp->st_top]);
92}
93
94void
95stack_push(stk_t *sp, void *data)
96{
97	sp->st_top++;
98
99	if (sp->st_top == sp->st_nument) {
100		sp->st_nument += STACK_SEEDSIZE;
101		sp->st_data = xrealloc(sp->st_data,
102		    sizeof (void *) * sp->st_nument);
103	}
104
105	sp->st_data[sp->st_top] = data;
106}
107
108int
109stack_level(stk_t *sp)
110{
111	return (sp->st_top + 1);
112}
113